Record changer apparatus



May 4, 1954 BURT 2,677,549

RECORD CHANGER APPARATUS Filed July 16, 1948 2 Sheets-Sheet 1 INVENTOR. w, fimovflBue'r .M 19 W ATTORNEY May 4, 1954 Filed July 16, 1948 F. B. BURT RECORD CHANGER APPARATUS 2 Sheets-Sheet 2 INVENTOR.

Fiewv B. 8021' Maw ATTORNEY Patented May 4, 1954 UNITED STATES PATENT OFFICE Bendix Aviation Corporation,

South Bend,

Ind, a corporation of Delaware Application July 16, 1948, Serial No. 39,030

7 Claims.

ihis invention relates to automatic phonographs and more particularly to trip mechanisms therefor.

In the mechanism of the present invention the power or actuating force required for operating the trip mechanism is taken directly from the main drive shaft to which other moving parts of the phonograph are connected. This has a distinct advantage over phonographs or record changers which rely on the tone arm to impart the actuating force to the trip mechanism. In the latter type construction there is the likelihood of forcing the needle of the pickup out of the grooves of a record if the actuating force required to operate the trip mechanism is too great.

It is a principal object of the invention to provide a simple, rugged, automatic phonograph which requires a minimum of attention during the playing of a stack of records.

Another object of the invention resides in the provision of a trip mechanism operable when the stylus, which is carried by the pickup arm, moves out of a playing groove into a non'playing groove to thereby initiate a record changing cycle.

A further object of the invention resides in the provision of a trip mechanism which receives its actuating force from a power source connected directly thereto.

A very important object of the invention resides in the provision of a trip mechanism which may be manually operated to start cycling of the machine before a record has been completely played.

A yet further object of the invention resides in the provision of a velocity controlled trip mechanism which is rendered operative upon movement of the pickup into the tripping grooves of a rec- 0rd.

A. further object of the invention is to provide a phonograph apparatus having cycling means controlled by a velocity responsive trip mechanism.

The above and other objects and features of the invention will be apparent from the following description of the apparatus taken in connection with the accompanying drawing which forms a part of this specification, and in which:

Figure 1 is a vertical section taken on the lines i-! of the automatic phonograph of Figure 2 incorporating the invention, with parts omitted for clarity;

Figure 2 is a horizontal section taken on the lines 22 of the automatic phonograph of Figure 1, with parts omitted for clarity;

Figure 3 is a view taken on the lines 33 of Figure 1 showing the trip mechanism of the invention with parts of the phonograph omitted for clarity, and with parts in phantom outline to more clearly show the relationship of the parts of the mechanism;

Figure 4 is a sectional View taken on the lines tl of Figure 2; and m Figure 5 is a view of two of the levers of the trip mechanism.

Referring now to Figures 1 and 2 the reference numeral l9 designates a platform of a phonograph mechanism which may be supported in any suitable manner on vibration clamping mountings, such as springs, not shown. The cycling mechanism of the phonograph apparatus includes an electric motor i2 that is carried by a bracket Hi bolted to the underside of the platform H], by a bolt it, which threadedly engages the platform. A gear box 18 is formed with an integral tubular extension 2% having a flange 22 at its outer end for securing the gear box to the motor, in any suitable manner. The motor i2 is provided with a shaft 24 having an end extending through the tubular extension it into the gear box A8. A vertically extending shaft 26 has one end terminating in the gear box it, where the shaft is drivably connected through gearing, not shown, to the motor shaft 24. A pinion gear 28 is fixed to the other end of shaft 25. The pinion gear 253, which rotates continually when the phonograph apparatus is being played, is provided with interrupted gear teeth 3% and continuous gear teeth 32 for a purpose hereinafter disclosed.

A record supporting mechanism or turntable 34 is swingably mounted on the upper end of shaft 2%, to the lower end of which a gear 33 is fixed for driving engagement with a gear sector at. A lever it connects the gear sector it to a circular cam element 44 provided with interrupted gear teeth it on its periphery for engagement with the pinion gear 28.

For releasably supporting a stack of records above the turntable three properly spaced shafts 18 are provided. The shafts extend vertically above and below the platform iii. ihe upper ends of the shafts 18 are equipped with record slicing and supporting devices, not shown. The lower ends of the shafts carry sprockets fixed- 1y secured to the shafts, in any suitable manna A continuous chain 52 passes over the three sprockets so that the shafts and consequently the slicers are driven simultaneously upon rotation of said cam wheel it, which is drivably connected to one of said sprockets through a link 5%.

A tone arm 56, having a pickup 5.8 articulated thereto, is mounted on a vertical shaft 68 supported laterally in a, double hub 52 integral with the platform I and extending above and below. The pickup or reproducer 58 is carried in gimbals 64 of the tone arm and is of a common form except that it is equipped with a double pointed needle 66 arranged to engage in the grooves in either the top or the bottom side of a record which is supported on the turntable. The lower end of the vertical shaft 66 is rounded at 88 so as to ofier a minimum of friction to its sliding contact with an arm 'iti, of a bell crank i2, which raises and lowers the tone arm to the desired position above or below a record, as the case may be. The bell crank is supported on the underside of the platform and has its fulcrum at it. An arm 76 of the bell crank is disposed at right angles to the arm I6 and is provided with a roller I8 arranged for rolling contact with an inner cam track 2t and an outer cam track 82 formed in the cam wheel 44. When the roller :3 rides in the inner cam track the tone arm is positioned for playing the top side of a record. With the roller in the outer cam track 32, the tone arm will come to rest vertically in a position for playing the bottom side of a record.

That part of the double hub 32 which depends below the platform It, has a reduced diameter 84, which forms a bearing for a friction drive wheel 85, held in position by a snap ring 88. The periphery of the wheel 86 is constructed of a highly frictional material to insure traction b tween the wheel and a flange 9d integral with one end of a reciprocating lever 92, the other end of which is slotted at E l to embrace a reduced section 96 of a hub 98. Said other end of the lever $2 is equipped with a cam follower which fits into a groove Iill formed in the top side of the cam 44. The end of the reciprocat ng lever with which the flange so is integral is also slotted at I82 to embrace the reduced diameter 8 3 of the hub I52. The slotted end )2 is held in position by washers H13 encircling the reduced portion E of the hub 82, and located one on each side of the lever 92. A spacer is interposed between the lower washer and the top side of wheel 85. The width of slot I02 is greater than the reduced diameter 84 to permit relative lateral movement between the hub 62 and the end of the reciproeating lever 92 circumscribing said hub. One end of slot I02 is formed with a cam 99 which rides on the reduced diameter 8 of the hub, when the reciprocating lever is moved to the position shown in Figure 2 to thereby cause the flange as to move away from the periphery of wheel 85 so as to arrest the driving action imparted to the wheel through reciprocation of the lever. A spring I04 tends to rotate the lever 92 so that the flange 530 is in frictional engagement with the periphery of wheel 86.

The wheel 8% is equipped with a pair of diametrically opposed driving pins !@5 which depend from the wheel for engagement with a cross bar I05 carried by the shaft 66, see Figure 3. The cross bar is formed with diametrically positioned slots It}? and I08 for sliding engagement with the driving pins W5. This arrangement between the driving wheel 86, which rotates the tone arm laterally, and the vertical shaft 66, which posi tions the tone arm vertically, provides for concurrent raising or lowering action of the tone arm in conjunction with lateral or swinging movement thereof.

The invention herein resides in the provision of a trip mechanism for sensing the end of a playing 4 groove of a record to thereby initiate cycling of the automatic phonograph. To this end there is provided a velocity sensitive mechanism including a lever IIO arranged to swing periodically about the pivot III. This periodic movement is imparted to the lever by having one end thereof biased by a spring II2 into contact relationship with a revolvable cam II3, suitably secured to the drive shaft 26. To the other end of the lever i It is pivotally mounted an actuating pin 2 I4 for pushing engagement with one end of a lever H5 which is pivotally carried at I IE on the underside of the platform I0. Overlying said other end or the lever H0 and pivotally carried at HI, is lever II? arranged for limited relative angular movement with respect to lever I it. This limited movement, or lost motion between levers 4 Hi and I I? is accomplished by the use of a pin I It which is mounted on lever I I0 and projects into an oversized opening H9 of the lever II'I. For positioning the actuating pin II4 for pushing engagement with the lever I I5 a pin positioning member I20 is rotatably mounted at one end of the lever II'I. As best shown in Figures 3 and 4 the pin positioning member is provided with a rounded end I2I which rides on the periphery of drive wheel 86 to be frictionally driven thereby. A spring I22, overlies spring I i2, and is arranged to have one end fastened to lever Ii'i at 23 to thereby urge the rounded end I2i of the pin positioning member I20 into contact relationship with the periphery of wheel 85. The pin positioning member I20 is provided with a slot i24 which receives the pivoted end of the actuating pin i It.

The slot I24 is of sufficient length to permit angular relative movement between levers 5; t and i ii, as aforementioned, and wide enough to allow the member Hi? to swing angularly about its pivot to thereby impart angular movement to actuating pin lI i, which has an end I25 slidably carried in an upturned element I25 of the member I229. As best shown in Figures 3 and 4, a spring I2? rotates the member I20 in a counterclockwise direction against the end I28 of the actuating pin which acts as a stop.

Movement of the pickup arm toward the center of a record, as during the playing thereof, under the influence of the stylus 66 tracking inwardly toward the center, rotates the wheel 88 counterclockwise which causes the pin positioning member I20 to swing clockwise, see Figure 3, against the action of spring I21, to thereby move the end I25, of the pin I I4, to the left. If the end I25 of the pin I I4 is swung far enough to the left, depending on the velocity of the wheel 86, it will be in a position to engage a projection I29 integral with one end of the lever H5. For each revolution of the shaft 26 the cam H3 engages the right end of lever III! to thereby swing the left end of said lever in a counterclockwise direction so that the rounded end i2! of the member I20 is moved away from the periphery of wheel 86, at which time the spring I27 rotates the member back to its original position against the end I28 of the pin H4. Each time the lever II it is rotated the actuating pin I I4 is also thrust forward a given amount. In this connection it should be noted that lever I I3 can swing a given angular distance before lever II! will be rotated because of the slight amount of travel of pin H8 in the oversized opening H9. This arrangement will permit thrusting the end I25 of the pin H4 forward to engage the projection I29 before the rounded end I 2I is actually out of contact with the drive wheel 86. Whether or not the end I25 of theactuating pin engages the projection are of the lover I I before the pin positioning member 120 is returned by spring I21, depends on how far the end I25 is swung before the pin positioning member is moved out of driving engagement with the wheel 86. The greater the velocity of the wheel 86' the greater the swing of end I25 before the pin positioning member is moved out of contact with the wheel 86. The elements iiii, m, H4, I20, and I2! provide a mechanism which responds to the predetermined velocity of said wheel 86, and isactuable by said cam lit to actuate the lever I15. Element IE4 is swingable a first predate mined distance in accordance with the velocity imparted to said wheel 86 when the pickup arm is tracking in the playing grooves of the record and swing'able a second predetermined distance, which is greater than the first predetermined distance in accordance with the velocity imparted to said wheel when the pickup arm is tracking in the tripping groove of said record.

Lever H5 is normally urged against a stop 5353 by a spring I3l having one end fastened to one end of the lever and the other end of the spring is secured to a pin E32 carried on the underside of the platform. The other end of the lever H5 is provided with a downwardly projecting prong I33 which engages an upwardly projecting prong iiii, carried by a crank arm I36, pivotally fulcrumed on pin 35 to the top side of the cam M. A toothed member i3! is pivotally linked to one end of the crank arm for engagement with the interrupted pinion gear 38. A spring I38 biases the crank arm in a direction tending to move the toothed member into engagement with the interrupted gear tooth. The lever I I5, crank arm I3, and toothed member 1-31 provide a latch device actuable by said pin 8 It to initiate cycling. However, actual engagement between the toothed member and the interrupted gear tooth of pinion it is normally prevented by the upwardly projecting prong i3fl engaging the downwardly projecting prong I33. Any rotation of lever H5, such as would be imparted thereto by the actuating pin lid, will disengage the downwardly projecting prong I33 from the prong I34, to thereby permit crank arm I36 to be rotated under the influence of the spring I38. This action causes the toothed member I31 to move into meshing relationship with the driving pinion gear 28. ihe cam is now drivably connected to the pinion gear so that rotation of the cam will rotate the teeth it thereof into registry with the continuous gear teeth 32 of the driving pinion gear 28.

It is essential that the trip mechanism does not interfere with the tone arm movement during the cycling phase of the phonograph. To insure such non-interference the lever IIO is provided with a cam MI which slides into a recess i lil, located in the periphery of the circular cam element t l, during a non-cycling period. This recess M2 is of sufficient length to allow the end 925 of pin I id to become disengaged from the projection I29 and to swing to the right, as shown in Figure 3, under the influence of spring I22 before the cam I41 is permitted to ride onto the periphery of the cam 4t. When the cam IM rides onto the periphery of the cam 44 the rounded end I2I of the member I20 will be swung out of contact with the wheel 86.

With reference to Figure 2, a tie rod I44 connects the lever H5 to the push button selector control M5 in a manner such that manually depressing any one of the buttons I46 downwardly a predetermined distance will rotate lever H5 to disengage prongs I33 and I34 and hence release the lever I36 on which the toothed member It? is carried. The toothed member is now moved into engagement with the pinion gear. The manual control permits cycling the phonograph, that is, changing records, anytime during the playing period. This push button selector mechanism forms no part of the present invention and will therefore not be described in detail.

In sensing the end of the playing period of a record the trip mechanism functions as follows: As the stylus track's inwardly toward the center or a record the tone arm swings inwardly, thereby revolving the wheel 86, which in turn rotates the pin positioning member I220. The stylus and hence the pickup arm track inwardly toward the center of a record a predetermined distance during each revolution of the turntable as the record is being played. Since the tripping or non-playing grooves of a record have a greater lead than the playing grooves the wheel 86 will have a greater velocity per revolution of the turntable when the stylus is tracking in the non-playing or tripping grooves than when tracking in the playing grooves.

The cam II3, which rotates at approximately the same speed as the record rides against an end of the lever i it every revolution causing it to swing about pivot i i I. The initial movement of lever its under the influence of cam H3 is not enough to move the member 520 out of contact with the wheel so that the pin lid is thrust forward a predetermined distance depending upon the angle between the member iii) and the lever i It. Continued rotation of cam i It further swings the lever i Ii) angularly, which thrusts the pin i forward an additional predetermined distance and lifts the rounded end I2I, of the pin positioning member, out of contact with the wheel 85. Spring bit then returns the member it?! to its original position and the action is repeated. When the pickup arm reaches the end of a record, that is, when the stylus passes into a non-playing or tripping groove where the lead is greater than the lead of a playing groove, the pickup arm, and hence the wheel 85 will rotate at a greater velocity to thereby swing the pin its at an angle such that the pin will be thrust into the projection E29 of lever H5 before the rounded end I2I of the member 526 is moved out of contact with the wheel 86. This releases the toothed member I31 and thereby initiates a cycle.

Although this invention has been described in connection with certain specific embodiments, the principles are susceptible of numerous other applications that will readily occur to persons skilled in the art.

Having thus described the various features of the invention, what I claim as new and desire to secure by Letters Patent is:

1.. In a phonograph apparatus having means for supporting a record during the playing therecf and a pickup arm constituted to cooperate with the grooves in said record, a drive shaft having a pinion gear mounted thereon, cam means con nectible to the pickup arm and having teeth arranged thereon for engagement with said pinion gear, a wheel constructed and arranged to be rotated at a predetermined velocity by said pickup arm as it tracks in the grooves of said record, a latch device carried by said cam means for drivably connecting said cam means to said pinion gear and having an element engageable with said pinion gear, said element normally releasably held out of engagement with said pinion gear, a mechanism drivably connected to said wheel to respond to the predetermined velocity thereof and operatively related to said latch device to actuate the same to release said element for engagement with said pinion gear, said mechanism including a lever pivoted intermediate its ends and pivotally mounting a swingable member on one end thereof, said swingable member having one end arranged in frictional relationship to said wheel and its other end positioned for engagement with said latch device, said swingable member being constituted to rotate a predetermined distance in response to the predetermined velocity of said wheel when the pickup arm is tracking in the tripping groove of said record, and a cam carried by the drive shaft and engageable with the other end of said lever to impart rotation to said lever to thereby thrust said swingable member forward for engagement with the aforementioned latch device.

2. In a phonograph apparatus having a device for supporting a record during the playing thereof and a pickup device constructed and arranged to cooperate with the grooves in said record, a rotatable shaft having a gear mounted thereon, a rotatable cam member having teeth thereon arranged for meshing relationship with said gear, means connecting said record supporting device and said pickup device to said cam member, a latch mechanism for controlling engagement be tween the gear and cam member and normally disconnecting said gear from said cam member, said latch mechanism operable upon movement of said pickup device into the tripping groove of said record to drivably connect said gear to said cam member, and a velocity sensitive mechanism responsive to movement of said pickup device in the grooves of said record, said velocity sensitive mechanism including a lever pivoted intermediate its ends, with one end lying adjacent said rotatable shaft and the other end lying adjacent said latch mechanism, said other end of the lever being provided with an actuating element operatively related to said pickup device to be driven at one rate or speed when the pickup device is following in the playing groove of the record and at a dilrerent rate of speed when the pickup device is following in the tripping groove of a record, and means carried by the rotatable shaft for imparting a periodic rotation to said other end of the lever, said latch mechanism having a portion thereof lying in the path of said actuating element to be driven thereby when the latter is driven at said different rate of speed.

3. In a phonograph apparatus having a pickup arm with a stylus for following in the grooves of a record to be reproduced, power means, means drivably connecting said pickup arm to said power means for positioning said pickup arm with respect to a record and comprising driving and driven gears, a latch mechanism having a part carried by one of the gears for engagement with the other gear, said part being normally releasably held out of engagement with said other gear for disconnecting said pickup arm from said power means when said arm follows in the playing groove of said record, said part being releasable for engagement with said other gear for connecting said pickup arm to said power means when said arm follows in the tripping groove of said record, an actuating lever having one end operatively related to said power means, and means supported on the other end of said lever and movable into a position for engagement with said latch mechanism under the influence of the pickup arm when the latter follows in the tripping groove of a record for actuating said latch mechanism to thereby cause release of said part.

4. In a phonograph apparatus having a pickup arm with a stylus for following in the grooves of a record to be reproduced, a rotatable shaft provided with a gear, means drivably connecting said pickup arm to said gear for positioning said pickup arm with respect to said record and comprising a cam constructed and arranged to be drivably connected to said gear, a latch mechanism having a part arranged on the cam to disconnect said pickup arm from the gear when said arm follows in the playing groove of said record, said part being moved to a position to connect said pickup arm to said gear when said arm follows in the tripping groove of said record, means operatively related to said pickup arm including a first element rotatable in an are when said pickup arm follows in the playing groove of said rec-- 0rd and rotatable in a greater are when the arm follow in the tripping groove of the record and a second element arranged to follow the move-- ment of the first element and radially actuable with respect to the first element, and means for imparting an actuating force to said second element when said first element is rotated in said greater are to cause actuation of the latch mechanism, said last-named means including a lever pivoted so that one of its ends is operatively related to said shaft to be rotated thereby and its other end is operatively related to said latch mechanism via said second element.

5. In a phonograph apparatus having a pickup arm with a stylus for following in the grooves of a record to be reproduced, power means, means drivably connecting said pickup arm to said power means for positioning said pickup arm with respect to a record and comprising driving and driven gears, a latch mechanism having a part carried by said driven gear for engagement with said driving gear, said part being normally rcleasably held out of engagement with said driving gear for disconnecting said pickup arm from said power means when said arm follows in the playing groove of said record, said part being releasable for engagement with said driving gear for connecting said pickup arm to said power means when said arm follows in the tripping groove of said record, an actuating lever having one end operatively related to said power means, and means supported on the other end of said lever and movable into a position for engagement with said latch mechanism under the infiuence of the pickup arm when the latter follows in the tripping groove of a record for actuating said latch mechanism to thereby cause release of said part, said movable means receiving its actuating force from said power means by means of said lever.

6. In a phonograph having a turntable for supporting a record during the reproduction thereof, a pickup arm with a stylus for following in the grooves of said record, power means, means drivably connecting said pickup arm to said power means for positioning said pickup arm with respect to said record and comprising driving and driven gears, a latch mechanism having a part supported on said driven gear for engagement with said driving gear, said part being normally releasably held out of engagement with said driving gear for disconnecting said pickup arm from said power means when said pickup arm follows in the playing groove of said record, said part being releasable for engagement with said driving gear for connecting said pickup arm to said power means when said pickup arm follows in the tripping groove of said record, an actuating lever having one end operatively related to said power means and its other end operatively related to said latch mechanism, and means mounted on said other end of the lever operatively related to said pickup arm and to said latch mechanism and including an element to be moved to a first predetermined position under the influence of the pickup arm when the latter follows in the tripping groove of said record and moved to a second predetermined position by said lever to cause engagement of said element with said latch mechanism thereby causing said part to be released for engagement with said driving gear.

'7. In a phonograph apparatus having a pickup arm with a stylus for following in the grooves of a record to be reproduced, a rotatable shaft provided with a gear, means drivably connecting said pickup arm to said gear for positioning said pickup arm with respect to said record and comprising a cam constructed and arranged to be drivably connected to said gear, a latch mechanism having a part arranged on the cam for driving engagement with said gear and manually out of engagement therewith when said arm follows in the playing groove of said record, first and second levers pivoted about a common pivot, said second lever having one end operatively related to said power means, a first element rotatable about a center on said first lever, and a second element operatively connected to said latch mechanism and rotatable about a center on the other end of said second lever, said first element drivably connected to said pickup arm and to said second element to rotate the latter about its center, said second element being actuable by said second lever to cause actuation of the latch mechanism.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,348,257 Kahl et a1 May 9, 1944 2,506,926 Johnson May 9, 1950 2,568,496 Hall Sept. 18, 1951 FOREIGN PATENTS Number Country Date 572,688 Great Britain Oct. 18, 1945 

